Insect chemosterilant methods employing phosphates



United States Patent 3,492,405 INSECT CHEMOSTERILANT METHODS EMPLOYINGPHOSPHATES Philip C. Hamm, Glendale, Mo.,- assignor to Monsanto Company,St. Louis, Mo., a corporation of Delaware No Drawing. Filed Mar. 30,1967, Ser. No. 626,985

Int. Cl. A01n 9/36 US. Cl. 424-224 7 Claims ABSTRACT OF THE DISCLOSUREThis invention relates to chemosterilant compositions and to methods forthe control or eradication of insect populations. 1

The term insect" is used herein in its broad common usage to includespiders, mites, ticks and like pests which are not in the strictbiological sense classified as insects. Thus, the usage herein conformsto the definitions provided by Congres in Public Law 104, the FederalInsecticide, Fungicide, and Rodenticide Act of 1947, Section 2,subsection b, wherein the term insect is used to refer not only to thosesmall invertebrate animals belonging mostly to the class Insecta,comprising six-legged usually winged forms, as beetles, bugs, bee,flies, and so forth, but also to other allied classes of arthropodswhose member are Wingless and usually have more than six legs, asspiders, mites, ticks, centipedes, and wood lice.

In accordance with this invention is has been found that insects can becontrolled or eradicated by a method which comprises exposing the insectto amount of a compound of the formula wherein R and R are haloalkyl ofnot more than 4 carbon atoms and 3 halogen atoms (Cl, Br, F and I), andR is alkyl of not more than 18 carbon atoms.

In the above formula R and R can be haloalkyl, for example,chloromethyl, iodomethyl, bromomethyl, fluoromethyl, chloroethyl,iodoethyl, bromoethyl, fluoroethyl, dichloroethyl, diiodoethyl,dibromoethyl, difluoroethyl, chloro-n-propyl, bromo-n-propyl,iodoisopropyl, bromon-butyl, bromo-tert-butyl, 1,3,3 -trichlorobutyl,1,3,3- tribromobutyl and the various homologues and isomers of haloalkylof not more than 4 carbon atoms and 3 halogen atoms. In the aboveformula R is alkyl such as methyl, ethyl, n-propyl, isopropyl, n-butyl,sec-butyl, isobutyl, tert-butyl, amyl, hexyl, heptyl, octyl, nonyl,decyl, undecyl, dodecyl and the various homologues and isomers of alkylof not more than 18 carbon atoms. Compounds of the above formula whereinR and R are of not more than 2 carbon atoms and 3 chlorine atoms, and Ris of not more than 12 carbon atoms are preferred.

For the sake of brevity, the compounds of the above formula which areuseful in the compositions and methods of this invention are referred tohereinafter as chemosterilants.

In carrying out the methods of this invention, the

a sterilizing 3,492,405 Patented Jan. 27, 1970 chemosterilants,admixtures thereof or compositions containing them are applied to theinsects or to their environment in an amount sufficient to exert asterilizing action. The chemosterilant compositions of this inventiongenerally contain from about 0.001% to about 99.99% by weight ofchemosterilant. The lower concentrations of chemosterilant areparticularly effective when the compositions are liquid, but it ispreferred to use higher concentrations of chemosterilant when thecompositions are semi-solid or solid. Compositions comprising from about0.001% to :about 5% by weight of chemosterilant are preferred with thosecomprising from about 0.001% to about 2% by weight being particularlyadvantageous. A wide variety of insects, for example, house flies (Muscadomestica), screw-worm flies (C0- chli'omyia hominivorax), Mexican fruitflies (Anastrepha ludens), oriental fruit fly, vinegar flies, eye gnats,stable flies, mosquitoes, boll weevils, pomace flies (Drosophilamelanogaster), Mediterranean fruit flies, cotton bollworm, codling moth,plum curculio, and the like, can be controlled or eradicated inaccordance with the methods of this invention.

Representative chemosterilants which can be used in the compositions andmethods of this invention include the following:

methyl-bis- 2'chloroethyl phosphate ethyl-bis- (2-chloroethyl) phosphatebutyl-bis- (2-chloroethyl phosphate octyl-bis- (Z-chloroethyl) phosphatedecyl-bis 2-chloroethyl phosphate dodecyl-bis- 2-chloroethyl) phosphateoctadecyl-bis- 2-chloroethyl )phosphate methyl-bis- (2-bromoethylphosphate decyl bis- (2-bromoethyl phosphate methyl-bis-(4,4-dichlorobutyl) phosphate decyl-bis- 4,4-dichlorobutyl) phosphateethyl-bis- (chloromethyl phosphate decyl-bis- (fluoromethyl) phosphatedecyl-bisbromomethyl) phosphate butylbis- (bromomethyl phosphate methyl-chloromethyl-2-chloroethylphosphatedecyl-chloromethyl-Z-chloroethylphosphatedecyl-chloromethyl-4=bromobutylphosphatedecyl-2-chloromethyl-2-bromoethylphosphate The following example willillustrate the invention.

Example Decyl-bis-(2-chloroethyl)phosphate is tested against the housefly using the following procedure:

Adult flies are fed granulated sugar containing 1.0% by weight ofdecyl-bis-(2-chloroethyl)phosphate. Chemosterilant sugar compositionsare prepared by adding 6 ml. of a solution or suspension ofchemosterilant in a volatile solvent to' 10 gms. of sugar. Thechemosterilant sugar compositions are allowed to dry, repulverized andplaced in emergence cages which contain newly emerged adult flies. Cagescontaining untreated sugar are used as control. All cages are suppliedwith ample water. After three days the flies are examined and themortality rate, if any, is noted. At the same time, a dish containinguntreated regular fly food consisting of 6 parts sugar, 6 parts powderednon-fat dry milk and one part powdered egg yolk is added to each cage.When the flies are 6 to 7 days old, one-half inch of moist ChemicalSpecialties Manufacturers Association medium in a soufll cup is placedin each cage for oviposition. A few hours later each souifi cup isremoved, filled with water and stirred to separate the egg masses intoindividual eggs. The eggs from all egg masses are mixed thoroughly andarandom sample of 100 eggs from each cageis placed a on a small piece ofwet black cloth. The black cloth is then placed on moist larval mediumin a rearing container. If no eggs are laid, oviposition medium isoffered again at intervals of one or two days until it has been offeredfive times or the. flies have oviposited. Three days after ovipositionthe eggs are examined and the percentage hatched is determined. Thelarvae that hatch crawl from the cloth into the rearing medium. About 7days after oviposition, the number of pupae are counted to determine thenumber of larvae that reach the pupal stage of development. The fliesfed decyl-bis-(Z-chloroethyl) phosphate gave a 26% hatch of eggs and 13pupae whereas the control flies gave a 91% hatch of eggs and 90 pupae.

In carrying out the methods of this invention, the chemosterilants canbe used alone or in combination with an adjuvant in liquid, solid orgaseous form. The chemosterilant compositions of the invention areprepared by admixing the chemosterilant with an adjuvant includingdiluents, extenders, carriers and conditioning agents to providecompositions in the form of finely-divided particulate solids,semi-solids, aerosols, solutions and dispersions or emulsions.- Thus thechemosterilant can be used with an adiuvant such as finely-dividedparticulate solid, a liquid of organic origin, Water, a Wetting agent,dispersing agent, an emulsifying agent or any suitable combination ofthese.

Typical finely-divided solid carriers and extenders which can be used inthe chemosterilant compositions of this invention include for example,the tales, clays, pumice, silica, diatomaceous earth, quartz, fullersearth, salt, sulfur, powdered cork, powdered Wood, Walnut flour, chalk,tobacco dust, volcanic ash, cottonseed hulls, wheat flour, soybeanflour, tripoli, ground corn cobs, charcoals and the like. Typical liquiddiluents include for example, kerosene, Stoddard solvent, hexane,benzene, toluene, water, acetone, ethylene dichloride, xylene, alcohols,diesel oil, glycols and the like. Typical liquefied gases for aerosolsinclude for example, haloalkyls such as dichlorodifluoromethane,fluorotrichloromethane, and the like. Typical semi-solid extendersinclude for example, soap, petroleum jelly, and the like.

The chemosterilants also can be employed in conjunction'with attractantsfor the particular insect being controlled. For example, they can beapplied to or admixed with attractants or baits such as sucrose,glucose, 1110- N lasses, protein mixtures, powdered egg yolk, powderedmilk, yellow corn grits, quincy granules, pumice granules, sexattractants, and the like.

The chemosterilant compositions of this invention, particularly liquidsand wettable particles, usually contain as a conditioning agent one ormore surface active agents in amounts sufficient to render a givencomposition readily dispersible in water or in oil. By the termsurface-active agen is understood that wetting agents, dispersingagents, suspending agents and emulsifying agents are included therein.

The term chemosterilant composition as used herein and in the appendedclaims includes not only compositions in a suitable form for applicationbut also concentrated compositions which require dilution or extensionwith a suitable quantity of liquid or solid adjuvant prior toapplication.

Surface-active agents which can be used in the chemosterilantcompositions of this invention are set out, for example, in Searle U.S.Patent 2,426,417, Todd U.S. 2,655,447, Jones U.S. Patent 2,412,510 andLenher U.S. Patent 2,139,276. A detailed list of such agents is also setforth by J. W. McCutcheon in Soap and Chemical Specialties, November1947, page 8011 et seq., entitled Synthetic Detergents; Detergents andEmulsifiersUp to Date (1960), by J. W. McCutcheon, Inc., and Bulletin13-607 of the Bureau of Entomology and Plant Quarantine of the U.S.D.A.In general, less than about parts by-weight of the surface active-agentis present per 100 parts by weight of chemosterilant composition.

The preferred chemosterilant compositions are in the form of wettablepowders, dusts, aqueous suspensions or solutions, hydrocarbonsolutionsand emulsifiable oils.

Wettable powders are water-'dispersible compositions containing one ormorejchernoster'ilant's and an inert solid extender. However, theirperformance issometimes aided by the inclusion of a wetting agent suchas those listed hereinbefore. Convenience in manufacture frequentlydemands the inclusion of an inert, absorptive grinding aid. Suitableclasses of grinding aids are natural clays, diatomaceous earth andsynthetic minerals derived from silican or silicate. Preferred grindingaids include attapulgite clay, diatomaceous silica, synthetic finesilica and synthetic calcium and magnesium silicates.

The inert finely-divided solid extender for the dusts can be ofvegetable or mineral origin. The solid extenders are characterized bypossessing relatively low surface areas and are poor in liquidabsorption. Suitable inert solid extenders for chemosterilant dustsinclude micaceous talcs, pyrophyllite, dense kaolin clays, groundcalcium phosphate rock and tobacco dustl' The wettable powders describedabove can also be used in the preparation of dusts. While such wettablepowders can be used directly in dust form, it is more advantageous todilute them by blending with the dense dust diluent. In this manner,dispersing agents, corrosion inhibitors and anti-foam agents may also befound as components of a dust.

Emulsifiable oils are usually solutions of chemosterilant inwater-immiscible or partially water-immiscible solvents together with asurfactant. Suitable solvents for the active ingredient of thisinvention include hydrocarbons and certain water-immiscible ethers,esters or ketones. Suitable surfactants are anionic, cationic andnonionic such as alkyl aryl polyethoxy alcohols, polyethylene sorbitolor sorbitan fatty acid esters, polyethylene glycol fatty esters, fattyalkylol amide condensates, amine salts of fatty alcohol sulfatestogether with long chain alcohols and oil soluble petroleum sulfonatesor mixtures thereof, The emulsifiable oil compositions generally containfrom about S te parts active ingredient, about 1 to 50 parts surfactantand about 4 to 94 parts solvent, all parts being by weight based on thetotal Weight of emulsifiable oil.

The chemosterilants useful in the c mpositions and methods of thisinvention can be prepared in various ways, e.g., by the process setforth in detail in U.S. Patent 3,010,988.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. Method for the control of house files by chemosterilization whichcomprises exposing house flies to a sterilizing amount of a compound ofthe formula wherein R and R are haloalkyl of not more than 4 carbonatoms and 3 halogen atoms, and R is alkyl of not more than 18 carbonatoms.

2. Method of claim 1 wherein R and R are chloroalkyl and R is decyl.

3. Method of claim 1 wherein R and R are-chloroethyl.

4. Method of claim 1 wherein R 'is decyl.

5.- Method of claim 1 wherein'the compound isdecylbis-(2-chloroethyl)phosphate.

6. Method of claim 1 wherein the compound is ethylbis- (Z-chloroethylphosphate.

3,492,405 5 6 7. Method of claim 1 wherein the compound is decyl- OTHERREFERENCES b1s-(2-chloromethy1)phosphate. Boikevec, Alexej, InsectChemosterilants, vol. VII,

References Cited 6143 1966' UNITED STATES PATENTS 5 ALBERT T. MEYERS,Primary Examiner 3,010,988 11/1961 Raffelson et a1 260-461 VINCENT D.TURNER, Assistant Examiner 3,093,536 6/1963 Loeifier 16722

